<p>The processing accuracy of bipolar plates significantly affects the performance of fuel cells. Electrochemical machining is widely used to fabricate parallel array channels, which are one of the most common structures on bipolar plates. Traditional electrochemical machining for parallel array channels produces different depths at the inlet and outlet regions due to the accumulation of electrolytic products along the direction of electrolyte flow. Additionally, when the electrolyte flows through the array channels, its convergence in the outlet region produces obvious flow marks. This paper describes an electrolyte periodic reversal method that ameliorates the effects of these defects. By switching the inlet and outlet of the electrolyte at regular times, the processing inconsistency caused by product accumulation is alleviated, and the flow marks caused by uneven electrolyte flow are flattened. Corresponding multi-physical and flow field simulations are carried out to confirm this hypothesis. Experimental analysis shows that electrolyte periodic reversal is conducive to improving the consistency of machining dimensions and alleviating flow marks.</p>